GOP's Rob Portman won't seek re-election
Sen. Rob Portman (R-OH)

Republican Sen. Rob Portman announced that he won't seek re-election when his term ends in two years.

The Ohio Republican made the announcement Monday, the same day the U.S. Senate is receiving the House impeachment article against former president Donald Trump, reported the Associated Press.

Portman told his hometown Cincinnati Enquirer that he's tired of congressional "gridlock."

The 65-year-old Portman won both of his previous elections easily but was widely expected to face a GOP primary challenge in 2022, especially after laying some of the blame for the Jan. 6 insurrection at the U.S. Capitol at Trump's feet.

"Both in his words before the attack on the Capitol and in his actions afterward, President Trump bears some responsibility for what happened on Jan. 6," Portman said shortly after the violent action.